Research Areas (permanent staff)Clicking on the names ABOVE will take you to the corresponding research descriptions below. Clicking on a name BELOW will take you to the scientist's individual webpage.

Develop rapid and sensitive methods for detection of enteric human pathogens from fresh produce, and examines the efficacy of current postharvest sanitizing procedures for survival of human pathogens. Molecular biology and genetics of survival mechanisms of human pathogens.

To develop and test novel methods to identify and characterize the parasites Cryptosporidium, Giardia, Microsporidia, and Blastocystis. Determine the presence of these organisms in livestock, associated domesticated and wild animal, as well as in edible foods, soil and water impacted by agriculture. Develop methods to reduce the number and virulence of these organisms in domesticated animals, food, and the environment.

Develop methods for the specific detection and enumeration of pathogenic forms of microorganisms in foods, soil, manure and water. Use those methods to describe the fate of pathogens on the farm and the routes for their transmission to foods.

The long-term research objective of this project is to develop and translate fundamental agroecological knowledge into recommendations and products to improve the economic position of organic farmers and to improve their ability to meet consumer demand for organic products. Objective 1 is to develop component technologies and management strategies that lead to improved productivity, enhanced soil and water conservation, and efficient nutrient cycling on organic farms. Objective 2 is to understand agroecological principles that drive the function of organic cropping systems and quantify ecosystem services.

Studies microbial ecology of zoonotic bacterial pathogens in leafy green production systems. Determines the effects of various environmental factors on the survival and dissemination of bacterial pathogens in various leafy green production environments. Develops effective agricultural practices to minimize pathogen contamination of fresh produce at pre-harvest and post-harvest production stages.

Develops functional relationships between environmental parameters and pathogen transport from animal manure; integrates information on pathogen transport and survival to improve and validate pathogen transport and dispersal models for prediction and risk assessment of pathogen transmission from animal manures to potable water and fresh produce.

Identifies mechanisms of introduction and persistence of Enterohemorrhagic Escherichia coli (EHEC) and Salmonella to fresh produce in pre-harvest environments. Determines molecular factors involved in the interaction of human pathogens with natural microflora on fresh produce and biofilm formation. Investigates novel antimicrobials as a produce wash to improve the safety of fresh produce.

To develop molecular methods to detect zoonotic protozoan parasites and apply these methods to specimens obtained from farms, wildlife, and surface waters in order to better understand the complex epidemiology of zoonotic diseases.

Research focuses on the survival, persistence and growth of the bacterial foodborne pathogen Escherichia coli O157:H7 in leafy green pre-harvest environments. E. coli O157:H7 has been associated with several high profile outbreaks associated with lettuce, spinach and other leafy greens. This work examines the ability of E. coli to internalize to spinach tissues through root uptake. His research team also examines the ability of E. coli O157:H7 to persist in pre-harvest environments (soil, water). The expression of virulence factors of E. coli O157:H7 on leafy greens stored under various conditions is also evaluated. Bacteriophages, viruses that target and kill E. coli O157:H7, are also being examined as a potential intervention against E. coli O157:H7 on leafy greens.

Studies the incidence and ecology of zoonotic bacterial pathogens in dairy production systems, to evaluate and develop on-farm control strategies that will minimize pathogen infection of the herd, maintenance in the environment, and subsequent contamination of the bulk milk.